DEEP INFRARED ARRAY PHOTOMETRY OF GALACTIC GLOBULAR-CLUSTERS - THE MAIN-SEQUENCE OF NGC-6171

Deep J,K IR-array photometry for individual Main Sequence stars in NGC 6171 reaching K similar to 18, about two magnitudes below the Turnoff , is presented. A first comparison with the theoretical isochrones com puted by Bergbusch and VandenBerg (1992) and transformed onto the near -IR plane by Bell (1992) shows that, after imposing a proper matching at the level of the giant branch, the models yield an adequate fit to the overall morphology of the available Colour Magnitude Diagrams. As already found by Davidge and Simons (1994) in M4, the offset one has t o apply to the model colors (V-J), (V-K) is however quite large (simil ar to 0.1 mag).